Nature and Behavior of Gases

According to kinetic theory:

• Gas particles have volume and experience attractive forces between particles.

• solids can physically change position at random.

• all matter consists of tiny particles and only those of liquids and gases are in constant motion.

• all matter consists of tiny particles that are in constant motion.

The process by which gases move from areas of high concentration to areas of low concentration until the concentration of the gas in the container is uniform is called

• diversion

• diffusion

• differential

• division

A helium-filled weather balloon has a volume of 240 L at 99 kPa pressure and a temperature of 0 ^oC. What is the mass (in grams to 3 significant figures) of the He in the balloon.

(He molar mass = 4.0026 g/mol)

Gases are compressible because

• they are composed of particles.

• they are mostly empty space and their container may be shrunk, forcing the particles closer together.

• they have mass and take up space.

• they form strong bonds with other gas particles.

A diagram in a chemistry book shows a magnified view of a flask of air as seen to the left. What do you think is between the dots (the dots represent air molecules)?

• air

• dust

• pollutants

• nothing

• oxygen

2.00 moles of an ideal gas has a pressure of 5.00 atm at a temperature of 155 ^oC. Calculate the volume (in L) this would occupy to three significant figures.

When a gas escapes its container through a tiny hole to an area of lower pressure this is called

• effusion

• effluent

• ineffable

• diffusion

The gas that can effuse or diffuse at a higher rate has

• the lower molar mass

• the higher molar mass

• the greater intermolecular attractions

• the least intermolecular attractions

Determine the total pressure of a gas mixture that contains oxygen, nitrogen, and helium. The partial pressures are: P_O2 = 27.0 kPa, P_N2 = 36.8 kPa, and P_He = 15.0 kPa.

• 14904 kPa

• 14.9 kPa

• 42.8 kPa

• 78.8 kPa

A sample of nitrogen gas has a pressure of 8.49 kPa at 467 K. If the volume does not change, what will the pressure be at 283 K?

• 14.01 kPa

• 5.14 kPa

• 15.56 kPa

• 1.26 kPa